Reversal and nonreversal shifts in monkeys.

Abstract

A group of infant monkeys and a group composed of adolescent and adult monkeys were trained to criterion in a Grice-type discrimination box and a Wisconsin General Test Apparatus, respectively, to respond to 1 dimension of a 2-dimen-sional discrimination task and then to respond either to the previously negative stimulus (reversal shift) or to the previously irrelevant dimension (nonreversal shift). Upon reaching criterion in the shift each S was required to learn the alternative type of shift. In both age groups the nonreversal shift was accomplished significantly more rapidly than the reversal shift. These data are discussed in relation to the performance of other species in similar problems.